The present invention relates to an airbag system mounted to a vehicle, such as a car, and specifically relates to a leg airbag system.
Various airbag systems are known to restrain occupants' bodies in a car collision, and include a driver airbag system that inflates and deploys from the rotational center of the steering wheel toward a driver seated in a driver seat. Such systems also include a passenger airbag that inflates and deploys from an instrument panel toward a passenger seat.
One airbag system includes a leg airbag system for preventing occupants' legs from colliding in a collision with, for example, an interior panel in front of the seat, and for restraining the vicinity of the knees in order to prevent movement of the lower half of the occupants' bodies toward the front of the vehicle.
The leg airbag system generally includes an airbag disposed inside the interior panel (in the space on the back of the interior panel), a gas generator for inflating the airbag, and a lid that covers the airbag normally (when the high-speed mobile unit such as a car is not in a collision).
Such a leg airbag system is generally constructed such that the airbag is disposed in a folded state inside the interior panel, and the lid is mounted so as to cover the folded airbag. When a car, for example, collides head-on with an object, the gas generator generates a jet of gas. The gas is supplied to the airbag to open the lid with the inflation of the airbag permitting the airbag to inflate towards the exterior of the interior panel. Deploying between the interior panel and the lower legs of the occupant, the airbag prevents the occupant's lower legs from striking against the interior panel (hereinafter, this type of airbag that inflates forward of occupant's legs is referred to as a knee airbag).
Japanese Unexamined Patent Application Publication No. 2005-82025 (“Patent Document 1”) discloses a leg airbag system that includes a knee airbag and a gas generator, substantially disposed in the knee airbag, projects to an exterior of the airbag through a slit-like insertion opening of the knee airbag. Patent Document 1 further discloses an ignition control connector connected to the externally projecting end of the gas generator.
Patent Document 1 further discloses the basic structure of a leg airbag system including a knee airbag and a gas generator that passes through the insertion opening of the knee airbag.
In order to optimize an airbag system, a leg airbag system is still required to have improved airtightness and deployment performance.
Accordingly, it is an object of the present invention to provide an airbag system in which the deployment performance of an airbag can be improved by improvement in airtightness characteristic of the airbag.
Further objects and advantages of the invention are apparent from the following description of the invention.